(a) Technical Field
The present disclosure relates generally to an apparatus and a method for controlling torque reduction of a hybrid electric vehicle. More particularly, the present disclosure relates to an apparatus and a method for controlling torque reduction of a hybrid electric vehicle that performs torque reduction.
(b) Description of the Related Art
Generally, a hybrid electric vehicle is driven by an engine which generates torque from fuel combustion and an electric motor which generates torque from an electric battery. The hybrid electric vehicle includes a hybrid control unit (HCU) for controlling an engine operation of the hybrid electric vehicle, an engine control unit (ECU) for controlling an operation of an engine, a motor control unit (MCU) for controlling an operation of the driving motor, a transmission control unit (TCU) for controlling an operation of the transmission, and a battery management system (BMS) for managing a condition of a battery. Among the control units, the TCU requests torque reduction for preventing an increase of an engine speed or shock of a transmission during shifting.
Meanwhile, a traction control system (TCS) is a safety system for preventing wheel spin and improving driving stability by controlling a brake and an engine while starting or during acceleration. The TCS is implemented in a typical hybrid electric vehicle and requests torque reduction when wheel spin occurs while starting or during acceleration.
When the TCU/TCS requests torque reduction as described above, conventional methods perform torque reduction using a motor torque at first for rapid control and using an engine torque as needed. However, in this case, torque reduction cannot be performed completely when the demand torque of the TCS is too low or a battery state of charge (SOC) is too high. If the demand torque of the TCS is too low, the demand torque of the TCS cannot be satisfied by using the motor only; if the battery SOC is too high, the motor cannot output sufficient negative torque.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the related art that is already known in this country to a person of ordinary skill in the art.